The method of this invention is one particularly useful in the cutting of pattern pieces from sheet material in the general way shown by U.S. patent application Ser. No. 07/571,077, filed Aug. 21, 1990, entitled "Method and Apparatus For Cutting Successive Segments of Sheet Material With Cut Continuation" now U.S. Pat. No. 5,042,339, wherein the sheet material to be cut is of relatively long length and is cut progressively by moving one segment of the work material to a cutting station, cutting lines in such one segment of the work material while it is positioned at the cutting station, moving the next adjacent segment of the work material to the cutting station, cutting lines in said next segment while it is positioned at said cutting station, and repeating said movement of successive segments of the work material to and the cutting of them at said cutting station until the entire length of the work material has been cut. In the cutting of pattern pieces from work material by such segment-by-segment cutting it often occurs that a pattern piece will have a portion of it falling into one segment and another portion falling into an adjacent segment so that one part of the pattern piece is cut at one time while the involved segment is at the cutting station and another portion of it is cut at a later time while the adjacent segment is at the cutting station.
Where portions of a line a:.e cut at different times, as for example in the above-described cutting of a pattern piece having portions falling in segments of work material cut at different times, positioning and cutting errors tend to occur at the points where the cutting is interrupted, so that along the portion of a line of cut extending through an interruption point the portions of the material located on opposite sides of the line may not be completely separated from one another and may instead be connected to one another by uncut threads or other material bridges. This in turn seriously hinders further processing of the cut work material, especially the step of removing cut pattern pieces from the surrounding waste material.
The general object of this invention is therefore to provide an improved method for cutting a line in work material in a case where it is necessary to interrupt the cutting and which method assures that despite the interruption the portions of the material located on opposite sides of the line are cleanly and completely separated from one another.
A further object of the invention is to provide a method achieving the preceding object and also specifically applicable to the cutting of pattern pieces from the work material and which method may, if desired, be carried out in such way as to involve no invasion of the pattern piece by the cutting tool. That is, the method can maintain, if desired, the intended geometries or shapes of the pattern pieces to be cut from the work material.
Other objects and advantages of the invention will be apparent from the following detailed description of the preferred embodiments of the invention and from the accompanying drawings and claims.